<!DOCTYPE html>
<html lang="en">

<head>
	<meta charset="UTF-8">
	<meta http-equiv="X-UA-Compatible" content="IE=edge">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<title>Document</title>
</head>

<body>
	<script>
		function partial(fn, ...presetArgs) {
			return function partiallyApplied(...laterArgs) {
				return fn(...presetArgs, ...laterArgs);
			}
		}

		function ajax(url, data, callback) {
			// ..
		}

		var ajaxTest1 = partial(ajax, 'http://www.test.com/test1');
		var ajaxTest2 = partial(ajax, 'http://www.test.com/test1');

		var ajaxData = partial(ajaxTest1, { data: "" })

		debugger
	</script>
</body>

</html>